Hi, I have a new question sorry.
I read the whole readme file, the documentation on this website and these posts but I didn´t find a solution how this responsive design works.
I didn´t activate the tick box "disable the viewport meta tag" at the template Settings but it´s not working. I tried it with an activated tick box, but also no change. Did I miss any setting that I have to do? I changed nothing under Modules Settings (all Displays are activated). Do I have to change the site width? It didn´t work from the beginning I installed it.

Does someone has an idea what I did wrong or miss in the settings?

Your site is responsive, see image below.
What exactly do you mean?

Hi, it's not responsive on my iPhone 5s and 6. Looks like the normal website! What is strange as well is that your Demo Blog site is responsive on both of my phones.

I found the problem it´s regarding the domain I use at Strato. I created a redirection via Frame to my website and the responsive design is getting lost with this kind of redirection. I contacted the Strato support.

Problem solved.